A Modeling Experiment on the Grounding of an Ice Shelf in the Central Arctic Ocean During MIS 6
High-resolution chirp sonar subbottom profiles from the Lomonosov Ridge in the central Arctic Ocean, acquired from the Swedish icebreaker Oden in 1996, revealed large-scale erosion of the ridge crest down to depths of 1000 m below present sea level [Jakobsson, 1999]. Subsequent acoustic mapping duri...
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ftuninhampshire:oai:scholars.unh.edu:ccom-1565 2023-05-15T15:04:52+02:00 A Modeling Experiment on the Grounding of an Ice Shelf in the Central Arctic Ocean During MIS 6 Jakobsson, Martin Siegert, M Paton, Mark 2003-12-01T08:00:00Z application/pdf https://scholars.unh.edu/ccom/565 https://scholars.unh.edu/cgi/viewcontent.cgi?article=1565&context=ccom unknown University of New Hampshire Scholars' Repository https://scholars.unh.edu/ccom/565 https://scholars.unh.edu/cgi/viewcontent.cgi?article=1565&context=ccom Center for Coastal and Ocean Mapping Oceanography and Atmospheric Sciences and Meteorology Other Earth Sciences text 2003 ftuninhampshire 2023-01-30T21:32:51Z High-resolution chirp sonar subbottom profiles from the Lomonosov Ridge in the central Arctic Ocean, acquired from the Swedish icebreaker Oden in 1996, revealed large-scale erosion of the ridge crest down to depths of 1000 m below present sea level [Jakobsson, 1999]. Subsequent acoustic mapping during the SCICEX nuclear submarine expedition in 1999 showed glacial fluting at the deepest eroded areas and subparallel ice scours from 950 m water depth to the shallowest parts of the ridge crest [Polyak et al., 2001]. The directions of the mapped glaciogenic bed-forms and the redeposition of eroded material on the Amerasian side of the ridge indicate ice flow from the Barents-Kara Sea area. Core studies revealed that sediment drape the eroded areas from Marine Isotope Stage (MIS) 5.5 and, thus, it was proposed that the major erosional event took place during Marine Isotope Stage (MIS) 6 [Jakobsson et al., 2001]. Glacial geological evidence suggests strongly that the Late Saalian (MIS 6) ice sheet margin reached the shelf break of the Barents-Kara Sea [Svendsen et al. in press] and this gives us two possible ways to explain the ice erosional features on the Lomonosov Ridge. One is the grounding of a floating ice shelf and the other is the scouring from large deep tabular iceberg. Here we apply numerical ice sheet modeling to test the hypothesis that an ice shelf emanating from the Barents/Kara seas grounded across part of the Lomonsov Ridge and caused the extensive erosion down to a depth of around 1000 m below present sea level. A series of model experiments was undertaken in which the ice shelf mass balance (surface accumulation and basal melting) and ice shelf strain rates were adjusted. Grounding of the Lomonosov Ridge was not achieved when the ice shelf strain rate was 0.005 yr-1 (i.e. a free flowing ice shelf). However this model produced two interesting findings. First, with basal melt rates of up to 50 cm yr-1 an ice shelf grew from the St. Anna Trough ice stream across the section of the ridge where there is ... Text Arctic Arctic Ocean Ice Sheet Ice Shelf Iceberg* Kara Sea Lomonosov Ridge oden SCICEX University of New Hampshire: Scholars Repository Arctic Arctic Ocean Kara Sea St. Anna Trough ENVELOPE(69.500,69.500,80.750,80.750) |
institution |
Open Polar |
collection |
University of New Hampshire: Scholars Repository |
op_collection_id |
ftuninhampshire |
language |
unknown |
topic |
Oceanography and Atmospheric Sciences and Meteorology Other Earth Sciences |
spellingShingle |
Oceanography and Atmospheric Sciences and Meteorology Other Earth Sciences Jakobsson, Martin Siegert, M Paton, Mark A Modeling Experiment on the Grounding of an Ice Shelf in the Central Arctic Ocean During MIS 6 |
topic_facet |
Oceanography and Atmospheric Sciences and Meteorology Other Earth Sciences |
description |
High-resolution chirp sonar subbottom profiles from the Lomonosov Ridge in the central Arctic Ocean, acquired from the Swedish icebreaker Oden in 1996, revealed large-scale erosion of the ridge crest down to depths of 1000 m below present sea level [Jakobsson, 1999]. Subsequent acoustic mapping during the SCICEX nuclear submarine expedition in 1999 showed glacial fluting at the deepest eroded areas and subparallel ice scours from 950 m water depth to the shallowest parts of the ridge crest [Polyak et al., 2001]. The directions of the mapped glaciogenic bed-forms and the redeposition of eroded material on the Amerasian side of the ridge indicate ice flow from the Barents-Kara Sea area. Core studies revealed that sediment drape the eroded areas from Marine Isotope Stage (MIS) 5.5 and, thus, it was proposed that the major erosional event took place during Marine Isotope Stage (MIS) 6 [Jakobsson et al., 2001]. Glacial geological evidence suggests strongly that the Late Saalian (MIS 6) ice sheet margin reached the shelf break of the Barents-Kara Sea [Svendsen et al. in press] and this gives us two possible ways to explain the ice erosional features on the Lomonosov Ridge. One is the grounding of a floating ice shelf and the other is the scouring from large deep tabular iceberg. Here we apply numerical ice sheet modeling to test the hypothesis that an ice shelf emanating from the Barents/Kara seas grounded across part of the Lomonsov Ridge and caused the extensive erosion down to a depth of around 1000 m below present sea level. A series of model experiments was undertaken in which the ice shelf mass balance (surface accumulation and basal melting) and ice shelf strain rates were adjusted. Grounding of the Lomonosov Ridge was not achieved when the ice shelf strain rate was 0.005 yr-1 (i.e. a free flowing ice shelf). However this model produced two interesting findings. First, with basal melt rates of up to 50 cm yr-1 an ice shelf grew from the St. Anna Trough ice stream across the section of the ridge where there is ... |
format |
Text |
author |
Jakobsson, Martin Siegert, M Paton, Mark |
author_facet |
Jakobsson, Martin Siegert, M Paton, Mark |
author_sort |
Jakobsson, Martin |
title |
A Modeling Experiment on the Grounding of an Ice Shelf in the Central Arctic Ocean During MIS 6 |
title_short |
A Modeling Experiment on the Grounding of an Ice Shelf in the Central Arctic Ocean During MIS 6 |
title_full |
A Modeling Experiment on the Grounding of an Ice Shelf in the Central Arctic Ocean During MIS 6 |
title_fullStr |
A Modeling Experiment on the Grounding of an Ice Shelf in the Central Arctic Ocean During MIS 6 |
title_full_unstemmed |
A Modeling Experiment on the Grounding of an Ice Shelf in the Central Arctic Ocean During MIS 6 |
title_sort |
modeling experiment on the grounding of an ice shelf in the central arctic ocean during mis 6 |
publisher |
University of New Hampshire Scholars' Repository |
publishDate |
2003 |
url |
https://scholars.unh.edu/ccom/565 https://scholars.unh.edu/cgi/viewcontent.cgi?article=1565&context=ccom |
long_lat |
ENVELOPE(69.500,69.500,80.750,80.750) |
geographic |
Arctic Arctic Ocean Kara Sea St. Anna Trough |
geographic_facet |
Arctic Arctic Ocean Kara Sea St. Anna Trough |
genre |
Arctic Arctic Ocean Ice Sheet Ice Shelf Iceberg* Kara Sea Lomonosov Ridge oden SCICEX |
genre_facet |
Arctic Arctic Ocean Ice Sheet Ice Shelf Iceberg* Kara Sea Lomonosov Ridge oden SCICEX |
op_source |
Center for Coastal and Ocean Mapping |
op_relation |
https://scholars.unh.edu/ccom/565 https://scholars.unh.edu/cgi/viewcontent.cgi?article=1565&context=ccom |
_version_ |
1766336603623522304 |